Vanadium phosphate (or VPO) catalysts are known in the art as useful catalysts for several commercial processes, especially oxidation reactions such as the oxidation of butane to maleic anhydride or related compounds. Many different distinct forms of VPO exist, with the best known being (VO)2P2O7. The basic VPO crystalline structures can be modified with other metal cations either by doping, as solid solutions, or by substitution of V in the crystal structure. All of these modifications can lead to adjustments of catalytic properties.
Little work has been disclosed on VPO compositions containing antimony. U.S. Pat. Nos. 5,254,722 and 4,778,890 disclose SbVP3O12 and VSb2P0.85O7.62, respectively.